This disclosure relates generally to stereoscopic imaging systems. More particularly, but not by way of limitation, this disclosure relates to techniques for generating an image from a multi-camera imaging system that generates color images with high spatial resolution and high color fidelity.
Current stereoscopic imaging systems may utilize two full color image sensors or one full color image sensor and one monochrome image sensor. Stereoscopic imaging systems using two full-color cameras can provide high color fidelity. This is true, even in occlusion areas of the captured images, because both cameras include color image data. For example, one camera can provide color image data, even if the other camera cannot for some part of the captured scene. In addition, by using two color cameras, image registration can use both luminance-to-luminance comparisons and chrominance-to-chrominance comparisons. As used herein, “luminance” refers to the intensity component of the light received by a particular pixel on an image sensor (i.e., a measure of how bright the pixel is, independent of its color). As used herein, “chrominance” refers to the intensity of a particular color component of light received by a particular pixel on an image sensor. It is also noted that, color image processing, e.g., due to color filter array effects, can reduce an image's spatial resolution and increase the image's noise, both of which may result in reduced quality in the final output image.
Stereoscopic imaging systems using one full color image sensor and one monochrome image sensor can use the resulting monochrome image as the reference image during registration operations and the full color image to add color to the monochrome image. This provides a higher spatial resolution image than the dual full color system, while still containing color values. The resulting image can, however, lack any color information in areas of the captured scene that are only visible to the monochrome image sensor. As a result, color in occluded areas may need to be determined by informed estimation, which leads to visible color artifacts in the resulting image. In addition, because the monochrome image sensor lacks chrominance values, image registration can only be performed using luminance-to-luminance comparisons.